diff --git a/apps/resm/tasks.py b/apps/resm/tasks.py
index 756d620..5d9a11d 100644
--- a/apps/resm/tasks.py
+++ b/apps/resm/tasks.py
@@ -139,60 +139,70 @@ def get_abstract_from_elsevier(number_of_task:int = 20):
         for paper in qs[:number_of_task]:
             if not show_task_run(def_name):
                 break
+            original_status = paper.fetch_status
+            if original_status == "downloading":
+                return f"paper {paper.id} is already downloading"
+            paper.fetch_status = "downloading"
+            paper.save(update_fields=["fetch_status", "update_time"])
             try:
-                res = req.get(
-                    f"https://api.elsevier.com/content/article/doi/{paper.doi}",
-                    params=params,
-                    timeout=(3, 15)
-                )
-            except requests.RequestException:
-                err_msg = "elsevier_request_error"
-                break
-            if res.status_code == 200:
-                xml_str = res.text
                 try:
-                    root = etree.fromstring(xml_str.encode("utf-8"))
-                except etree.XMLSyntaxError:
-                    paper.save_fail_reason("elsevier_xml_error")
-                    continue
-
-                ns = {"dc": "http://purl.org/dc/elements/1.1/",
-                "ce": "http://www.elsevier.com/xml/common/dtd",
-                "xocs": "http://www.elsevier.com/xml/xocs/dtd",}
-                abstract = root.xpath("//dc:description/text()", namespaces=ns)
-                if abstract:
-                    PaperAbstract.objects.update_or_create(
-                        paper=paper,
-                        defaults={
-                            "abstract": abstract[0].strip(),
-                            "source": "elsevier"
-                        }
+                    res = req.get(
+                        f"https://api.elsevier.com/content/article/doi/{paper.doi}",
+                        params=params,
+                        timeout=(3, 15)
                     )
-                    paper.has_abstract = True
-                    paper.has_abstract_xml = True
-                    paper.fetch_status = "abstract_ready"
-                else:
-                    paper.save_fail_reason("elsevier_abstract_not_found")
-                    continue
+                except requests.RequestException:
+                    err_msg = "elsevier_request_error"
+                    break
+                if res.status_code == 200:
+                    xml_str = res.text
+                    try:
+                        root = etree.fromstring(xml_str.encode("utf-8"))
+                    except etree.XMLSyntaxError:
+                        paper.save_fail_reason("elsevier_xml_error")
+                        continue
 
-                paras = root.xpath("//ce:para", namespaces=ns)
-                has_fulltext = len(paras) > 0
-                if has_fulltext is False:
-                    rawtexts = root.xpath("//xocs:rawtext/text()",namespaces=ns)
-                    if rawtexts and len(rawtexts[0].strip()) > 2000:
-                        has_fulltext = True
-                if has_fulltext:
-                    paper.has_fulltext = True
-                    paper.has_fulltext_xml = True
-                    paper.fetch_status = "fulltext_ready"
-                    
-                paper.save_file_xml(xml_str)
-                paper.save(update_fields=["has_abstract", 
-                "has_abstract_xml", "has_fulltext", 
-                "has_fulltext_xml", "update_time", "fetch_status"])
+                    ns = {"dc": "http://purl.org/dc/elements/1.1/",
+                    "ce": "http://www.elsevier.com/xml/common/dtd",
+                    "xocs": "http://www.elsevier.com/xml/xocs/dtd",}
+                    abstract = root.xpath("//dc:description/text()", namespaces=ns)
+                    if abstract:
+                        PaperAbstract.objects.update_or_create(
+                            paper=paper,
+                            defaults={
+                                "abstract": abstract[0].strip(),
+                                "source": "elsevier"
+                            }
+                        )
+                        paper.has_abstract = True
+                        paper.has_abstract_xml = True
+                        paper.fetch_status = "abstract_ready"
+                    else:
+                        paper.save_fail_reason("elsevier_abstract_not_found")
+                        continue
 
-            elif res.status_code == 404:
-                paper.save_fail_reason("elsevier_doi_not_found")
+                    paras = root.xpath("//ce:para", namespaces=ns)
+                    has_fulltext = len(paras) > 0
+                    if has_fulltext is False:
+                        rawtexts = root.xpath("//xocs:rawtext/text()",namespaces=ns)
+                        if rawtexts and len(rawtexts[0].strip()) > 2000:
+                            has_fulltext = True
+                    if has_fulltext:
+                        paper.has_fulltext = True
+                        paper.has_fulltext_xml = True
+                        paper.fetch_status = "fulltext_ready"
+                        
+                    paper.save_file_xml(xml_str)
+                    paper.save(update_fields=["has_abstract", 
+                    "has_abstract_xml", "has_fulltext", 
+                    "has_fulltext_xml", "update_time", "fetch_status"])
+
+                elif res.status_code == 404:
+                    paper.save_fail_reason("elsevier_doi_not_found")
+            finally:
+                if paper.fetch_status == "downloading":
+                    paper.fetch_status = original_status
+                    paper.save(update_fields=["fetch_status", "update_time"])
 
     qs_count = qs.count()
     if show_task_run(def_name) and qs_count > 0:
@@ -315,8 +325,7 @@ def download_pdf(paper_id):
             msg = save_pdf_from_openalex(paper)
         return msg, current_from
     finally:
-        # 出错时恢复到原状态
-        if paper.fetch_status == "downloading" and paper.has_fulltext_pdf is False:
+        if paper.fetch_status == "downloading":
             paper.fetch_status = original_status
             paper.save(update_fields=['fetch_status', 'update_time'])